Neil Hedger joined the town's unit in July 1981 as a foundation member.

His son David followed 10 years later, and now his granddaughter, Mayson, 17, has started training as a junior volunteer.

Junior members between 15 and 18-years-old can can take part in some operational activities under supervision including rescues, community engagement and flood and storm response.

The unit's controller Hannah Morris said it was the first time three generations of the one family were part of the unit simultaneously.

Neil said when he joined he never imagined he'd help others with his family by his side.

"It's unbelievable," he said.

Neil, who was unit controller from 1989 to 2010, said he was inspired to join the SES after undertaking six years of volunteer paramedic work with Ambulance Victoria.

He said the need for the SES within the community was what kept him going for more than 40 years.

"When that pager goes off somebody is in trouble," Neil said.

David said he joined the unit as a way to spend more time with his parents.

"If I wanted to see them, it was my only option," he joked.

His mother, Maureen, was also an active member attending incidents until she was involved in a car crash. She is now involved socially with the unit.

David's wife Kim was also a volunteer until she had children. David said he hoped their son, Tai, 13, would join in the future.

David said it was a "happy dad moment" when Mayson joined.

Mayson, a year 12 student at Warrnambool's Brauer College, said no matter who she would go out on a job with upon completing training it was about being in the moment.

"It's just like get there and just get it done, it doesn't matter who you're with," she said.

"At the end of the day, they're there to help people no matter if you've had a falling out with someone, just get along with them."

Mayson is hoping to study nursing at university when she finishes school.